بررسي تحمل به خشكي در چهل ژنوتيپ در مرحله گياهچه

Investigation of Drought Tolerance at Seedling Stage in Forty Genotypes of Cotton (Gossypium hirsutum L.)

In order to examine drought tolerance of cotton genotypes at seedling growth stage, an experiment was conducted in greenhouse using 40 cotton genotypes and three drought levels (-1, -4 and -8 bars) in factorial arrangement with 3 replications and a randomized complete block design. Matric potentials were created based on soil moisture release curve. Percentage emergence, emergence rate, leaf number, leaf area, total dry weight (root and shoot) and root/ shoot raito were evaluated as affected by matric potentials. Results showed that all traits, except root/ shoot ratio, were decreased with increase in drought stress. Among the measured traits, Ieaf area was more sensitive and decreased greatly. Drought stress increased root/ shoot ratio, so that the greatest values were obtained at -8 bar. Overall, the genotypes Bulgar 433, TabeIadila and N. O. 200 at emergence stage and the genotypes Siokra, Barbadens, Bulgar 433 and Tabeladila at seedling growth stage were the most tolerant, while the genotypes Narabry and Sahel at emergence stage and Narabry, N.O. 259 and Deltapine at seedling growth stage were the most sensive genotypes.